Heretofore, many proposals have been made over many years about compounds having a phenoxypyrimidine skeleton and the utilization thereof as a herbicide. Representative literatures thereon are introduced below.
(1) Japanese Laid-Open Patent Publication No. 92978/1979
The following phenoxypyrimidine derivatives are disclosed as representative examples in this publication. ##STR2## wherein R'.sub.3 denotes a halogen atom.
It is disclosed in this publication that the above compounds have a miticidal action, but there is no suggestion about a herbicidal action.
(2) Japanese Laid-Open Patent Publication No. 117486/1979
In this publication, the following substituted phenoxypyrimidine derivatives are disclosed and suggested to have a herbicidal activity, but specific herbicidal activities are not disclosed at all. ##STR3##
(3) Japanese Laid-Open Patent Publication No. 55729/1979
In this publication, the following phenoxypyrimidine derivatives having a herbicidal activity are, for example, disclosed. ##STR4##
(4) Japanese Laid-Open Patent Publication No. 174059/1987
In this publication, a pyrimidine derivative represented by the following general formula and a herbicide containing it as an effective ingredient are disclosed. ##STR5## wherein X denotes O or S.
(5) Japanese Laid-Open Patent Publication No. 115870/1988
In this publication, a 2-phenoxypyrimidine derivative represented by the following general formula and a herbicide containing it as an effective ingredient are disclosed. ##STR6##
PROBLEMS TO BE SOLVED BY THE INVENTION
However, compounds disclosed in the above literatures do not necessarily have satisfactory performance in practical viewpoints on aspects such as weed killing spectrum, the amount thereof to be applied and crop selectivity, and the development of further excellent herbicides is desired.
The present inventors intensely studied for development of a herbicide having a wide weed killing spectrum and a high herbicidal effect and excellent in safety on crops, and as a result they found that phenoxymethylpyrimidine derivatives having such specific structure that a phenyl group binds to the 2-position of a di-lower alkoxypyrimidine through an oxygen atom and a methylene group exhibit an excellent herbicidal effect on not only annual but perennial weeds and, in addition, have high safety on crops, and completed this invention.
MEANS FOR SOLVING THE PROBLEMS
There is provided according to this invention a phenoxymethylpyrimidine derivative represented by the following general formula (1) ##STR7## wherein
X denotes a halogen atom, a lower alkyl group, a lower alkoxy group, a lower acyloxy group or a nitro group,
n denotes an integer of 0, 1 or 2,
Y denotes a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a substituted lower alkyl group, a substituted lower alkenyl group, a substituted lower alkynyl group, an alkali metal atom, an alkaline earth metal atom or an ammonium cation optionally substituted by alkyl group(s), and
R.sup.1 and R.sup.2 each independently denote a lower alkyl group.
In the definition of X, Y, R.sup.1 and R.sup.2 in the above general formula (1), specific examples of each group and atom are mentioned below.
Halogen atom:
For example, fluorine, chlorine, bromine, iodine, etc.
Lower alkyl group:
For example, lower alkyl groups having 4 or less carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl and text-butyl groups; etc.
Lower alkoxy group:
For example, lower alkoxy groups having 4 or less carbon atoms such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy and tert-butoxy groups; etc.
Lower acyloxy group:
For example, lower acyloxy groups having 4 or less carbon atoms such as acetyloxy and propionyloxy groups.
Lower alkenyl group:
For example, lower alkenyl groups having 4 or less carbon atoms such as vinyl, allyl, 3-butenyl and 1-methyl-2-propenyl groups.
Lower alkynyl group:
For example, propargyl, 2-butynyl, 3-butynyl, etc.
Lower alkylthio group:
For example, lower alkylthio groups having 4 or less carbon atoms such as methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, sec-butylthio and tert-butylthio.
Optionally substituted phenyl group:
Phenyl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2,4-dichlorophenyl and 2,4-dimethylphenyl groups, etc.
Optionally substituted heterocyclic group:
For example, pyridyl, thienyl, furyl, pyrimidyl, pyrazolyl, imidazolyl, triazolyl and thiazolyl groups are mentioned, and as their substituents halogens and lower alkyl, lower alkoxy and lower alkylthio groups, etc. are mentioned.
Alkali metal atom:
For example, sodium, potassium, etc.
Alkaline earth metal atom:
For example, calcium, barium, etc.
Ammonium cation optionally substituted by alkyl group(s)
For example, ammonium, methylammonium, dimethylammonium, trimethylammonium, ethylammonium, diethylammonium, triethylammonium, propylammonium and diisopropylammonium groups, etc.
Although, in the above general formula (1), X denotes a halogen atom, a lower alkyl group, a lower alkoxy group, a lower acyloxy group or a nitro group, and n denotes 0, 1 or 2, it is preferable, among them, that X is a halogen atom, a lower alkyl group or a lower alkoxy group and the most preferable is the case where X is a halogen atom, a methyl group or a methoxy group and n is 1. Further, when n is 1, the 6-position is the most preferable as the bond position of Xn on the benzene ring.
Y denotes a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a substituted lower alkyl group, a substituted lower alkenyl group, a substituted lower alkynyl group, an alkali metal atom, an alkaline earth metal atom or an ammonium cation optionally substituted by alkyl group(s), and as the substituent of the substituted lower alkyl group, the substituted lower alkenyl group and the substituted lower alkynyl group, there can be mentioned a halogen atom, a lower alkoxy group, a lower alkylthio group, a carboxyl group, a carboxyalkyl group, an optionally substituted phenyl group or an optionally substituted heterocyclic group. Preferable as the above Y is a hydrogen atom, a sodium atom, a lower alkyl group or an optionally alkyl-substituted ammonium cation (a lower alkyl group is suitable as the alkyl of the "alkyl-substituted"). Particularly preferable among them is a hydrogen atom, a methyl group, an ethyl group, an ammonium cation or an alkyl-substituted ammonium cation.
Although R.sup.1 and R.sup.2 each independently denote a lower alkyl group, the most preferable is the case where both R.sup.1 and R.sup.2 are methyl groups.
There are shown in Table 1 examples of the compounds of this invention represented by the above general formula (1).
TABLE 1 ______________________________________ ##STR8## Compound No. Xn Y ______________________________________ 1 -- H 2 -- CH.sub.3 3 -- C.sub.2 H.sub.5 4 -- CH.sub.2 CH.sub.2 OCH.sub.3 5 -- NH.sub.4 6 3-Cl H 7 3-Cl CH.sub.3 8 3-Cl C.sub.2 H.sub.5 9 3-Cl iso-C.sub.3 H.sub.7 10 3-Cl CH.sub.2 CHCH.sub.2 11 4-Cl H 12 4-Cl CH.sub.3 13 4-Cl C.sub.2 H.sub.5 14 4-Cl n-C.sub.4 H.sub.9 15 4-Cl ##STR9## 16 5-Cl H 17 5-Cl CH.sub.3 18 5-Cl C.sub.2 H.sub.5 19 5-Cl iso-C.sub.3 H.sub.7 20 5-Cl CH.sub.2 CO.sub.2 CH.sub.3 21 5-Cl CH.sub.2 C CH 22 6-Cl H 23 6-Cl CH.sub.3 24 6-Cl C.sub.2 H.sub.5 25 6-Cl n-C.sub.3 H.sub.7 26 6-Cl iso-C.sub.3 H.sub.7 27 6-Cl n-C.sub.4 H.sub.9 28 6-Cl CH.sub.2 CHCH.sub.2 29 6-Cl CH.sub.2 CHCH 30 6-Cl CH.sub.2 CH.sub.2 Cl 31 6-Cl ##STR10## 32 6-Cl Na 33 6-Cl NH.sub.4 34 6-Cl ##STR11## 35 -- ##STR12## 36 3, 6-Cl.sub.2 H 37 3, 6-Cl.sub.2 CH.sub.3 38 3, 6-Cl.sub.2 ##STR13## 39 3, 6-Cl.sub.2 CH.sub.2 CH.sub.2 OCH.sub.3 40 3, 6-Cl.sub.2 CH.sub.2 CH.sub.2 OC.sub.2 H.sub.5 41 3, 6-Cl.sub.2 CH.sub.2 CO.sub.2 CH.sub.3 42 3, 6-Cl.sub.2 ##STR14## 43 3, 6-Cl.sub.2 CH.sub.2 OC.sub.2 H.sub.5 44 6-CH.sub.3 H 45 6-CH.sub.3 CH.sub.3 46 6-CH.sub.3 C.sub.2 H.sub.5 47 6-CH.sub.3 CH.sub.2 CH.sub.2 Cl 48 6-CH.sub.3 CH.sub.2 OC.sub.2 H.sub.5 49 6-OCH.sub.3 H 50 6-OCH.sub.3 CH.sub.3 51 6-OCH.sub.3 CH.sub.2 CHCH.sub.2 52 6-OCH.sub.3 CH.sub.2 OC.sub.2 H.sub.5 53 6-OCH.sub.3 ##STR15## 54 6-Cl NH(C.sub.2 H.sub.5).sub.3 55 6-Cl K 56 6-Cl 1/2Ca 57 6-OCOCH.sub.3 CH.sub.3 58 6-OCOCH.sub.3 C.sub.2 H.sub.5 59 6-OCOCH.sub.3 iso-C.sub.3 H.sub.7 60 4-NO.sub.2 H 61 4-NO.sub.2 CH.sub.3 62 4-NO.sub.2 C.sub.2 H.sub.5 63 -- ##STR16## 64 -- ##STR17## 65 6-Cl CH.sub.2 CO.sub.2 CH.sub.3 66 6-Cl CH.sub.2 OC.sub.2 H.sub.5 67 6-Cl CH.sub.2 CH.sub.2 F 68 6-Cl ##STR18## 69 3-Cl ##STR19## 70 3-Cl CH.sub.2 CH.sub.2 OC.sub.2 H.sub.5 71 3-Cl CH.sub.2 CO.sub.2 CH.sub.3 72 3-Cl ##STR20## 73 6-Cl (CH.sub.3).sub.2 NH.sub.2 74 6-Cl n-C.sub.8 H.sub.17 NH.sub.3 75 6-Cl (C.sub.2 H.sub.5).sub.2 NH.sub.2 ______________________________________ PG,9
A compound (1) of this invention can, for example, be prepared according to the following process (Process A, Process B, Process C, Process D or Process E). These can appropriately be altered or appropriately be combined.
Process A ##STR21## wherein X, n, Y, R.sup.1 R.sup.2 have the same meaning as defined above, and Z denotes a halogen atom or an alkylsufonyloxy group.
In the above reaction formula of Process A, the compound represented by the formula (1) can be prepared by reacting the salicylic acid derivative of the above formula (2) with the pyrimidine derivative of the above formula (3) using a suitable base in the absence of a solvent or in the presence of a suitable solvent in the temperature range of -78.degree. C. to the boiling point of the solvent for 1 to 24 hours.
The compound (3) as a raw material for this reaction can, for example, be synthesized according to Journal of Heterocyclic Chemistry, 26, 913.
When a solvent is used in this reaction, there can, for example, be mentioned as examples thereof hydrocarbonic solvents such as benzene, toluene and xylene; halogenated hydrocarbon solvents such as dichloromethane and chloroform; ethereal solvents such as diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane; ketonic solvents such as acetone and methyl ethyl ketone; ester solvents such as methyl acetate and ethyl acetate; aprotic polar solvents such as dimethylformamide, dimethylsulfoxide and dimethylacetamide; acetonitrile; water; etc.
Further, as bases, there can be mentioned carbonates such as sodium carbonate and potassium carbonate; metal hydroxides such as sodium hydroxide and potassium hydroxide; metal alcoholates such as sodium methylate and sodium ethylate; alkali metal hydrides such as sodium hydride and potassium hydride; lithium amides such as lithium diethyl amide, lithium diisopropyl amide and lithium bis(trimethylsilyl) amide.
Process B ##STR22## wherein n, Y, R.sup.1 and R.sup.2 have the same meanings as defined above, and Z denotes a hydroxyl group, a halogen atom, an alkylsulfonyloxy group (e.g., a methanesulfonyloxy group, an ethanesulfonyloxy group or the like) or an arylsulfonyloxy group (e.g., a benzensulfonyloxy group or a paratoluenesulfonyloxy group or the like).
A compound represented by the formula (1) in the above reaction formula can be prepared by reacting a carboxylic acid represented by the formula (4) with a compound represented by the formula (5) in the presence of a suitable condensing agent in the absence or presence of a suitable solvent in the temperature range of under ice cooling to the boiling point of the solvent for 1 to 48 hours.
As solvents used for the reaction, there can be mentioned hydrocarbonic solvents such as benzene, toluene and xylene; halogenated hydrocarbon solvents such as dichloromethane and chloroform; ethereal solvents such as diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane; ketonic solvents such as acetone and methyl ethyl ketone; ester solvents such as methyl acetate and ethyl acetate; aprotic polar solvents such as dimethylformamide, dimethylsulfoxide, dimethylacetamide and acetonitrile; etc.
Further as condensing agents, there can be mentioned carbonates such as sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate; metal hydroxides such as sodium hydroxide and potassium hydroxide; metal alcoholates such as sodium methylate and sodium ethylate; alkali metal hydrides such as sodium hydride and potassium hydride; organic bases such as diazabicycloundecene; dehydrating-condensing agents such as dicyclohexylcarbodiimide. ##STR23## wherein X, n, Y, R.sup.1 and R.sup.2 have the same meanings as defined above, and W denotes a lower alkoxycarbonyl group, an optionally substituted aryloxycarbonyl group, a lower alkylsulfonyl group or an optionally substituted arylsulfonyl group.
In the above reaction formula, a compound represented by the formula (1) can be prepared by reacting a carboxylic acid of the formula (4) with a suitable activator represented by W-Cl in the presence of a suitable base to give an active intermediate represented by the formula (6), and then reacting the latter with a corresponding alcohol in the absence or presence of a catalyst.
As solvents used in the reaction, there can, for example, be mentioned hydrocarbonic solvents such as benzene, toluene and xylene; halogenated hydrocarbon solvents such as dichloromethane and chloroform; ethereal solvents such as diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane; ketonic solvents such as acetone and methyl ethyl ketone; ester solvents such as methyl acetate and ethyl acetate; aprotic polar solvents such as dimethylformamide, dimethylsulfoxide and dimethylacetamide; acetonitrile; water; etc.
As bases, there can be mentioned organic bases such as pyridine and triethylamine, and as activators, there can be mentioned alkyl chloroformates such as methyl chloroformate and ethyl chloroformate; aryl chloroformates such as phenyl chloroformate; alkylsulfonyl chlorides such as benzenesulfonyl chloride, methanesulfonyl chloride and ethanesulfonyl chloride; arylsulfonyl chlorides such as toluenesulfonyl chloride; etc. As catalysts, there can be mentioned dimethylaminopyridine, 4-pyrrolidinopyridine, etc. ##STR24## wherein X, n, Y, R.sup.1 and R.sup.2 have the same meanings as defined above.
A carboxylic acid represented by the formula (4) in the above reaction formula can be prepared by hydrolizing a compound represented by the formula (1) in the presence of an acid or a base in water or a mixture of water with a suitable solvent in the temperature range of under ice cooling to the boiling point of the solvent for 1 to 48 hours.
As solvents used in the reaction, there can be mentioned alcoholic solvents such as methanol, ethanol and isopropanol; hydrocarbonic solvents such as benzene and xylene; halogenous solvents such as dichloromethane, chloroform and dichloroethane; ethereal solvents such as diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane; ketonic solvents such as acetone and methyl ethyl ketone; aprotic polar solvents such as dimethylformamide, dimethylsulfoxide and acetonitrile; etc.
As acids, there can be mentioned inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid; arylsulfonic acids such as benzenesulfonic acid and paratoluenesulfonic acid; and Lewis acids such as boron trifluoride and aluminum chloride, and as bases, there can be mentioned alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide; etc. ##STR25## wherein n and X have the same meanings as defined above, and R.sup.3, R.sup.4 and R.sup.5 each independently denote a hydrogen atom, an aforesaid lower alkyl group or an aforesaid substituted lower alkyl group.
In the above reaction formula, a carboxylate salt represented by the formula (8) can be prepared by reacting a carboxylic acid represented by the formula (4) with an amine represented by the formula (7) in the absence or presence of a solvent.
As solvents used in the reaction, there can be mentioned alcoholic solvents such as methanol, ethanol and isopropanol; hydrocarbonic solvents such as hexane, benzene, toluene and xylene; halogenated hydrocarbon solvents such as dichloroethane, chloroform, dichloroethane and carbon tetrachloride; ethereal solvents such as diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane; ketonic solvents such as acetone and methyl ethyl ketone; ethyl acetate; acetonitrile; water; etc.
As amines of the formula (7), there can be mentioned ammonia; alkylamines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, isopropylamine, diisopropylamine, butylamine, isobutylamine, sec-butylamine, tertbutylamine, dibutylamine, amylamine, hexylamine, heptylamine, octylamine and nonylamine; aromatic amines such as aniline, N-methylaniline, N,N-dimethylaniline, N-ethylaniline and anisidine; etc.
The compounds of this invention are more specifically described below according to examples.